Mycophenolate mofetil for maintenance of remission in steroid-dependent autoimmune pancreatitis

Systemic corticosteroids represent the standard treatment for autoimmune pancreatitis with IgG4-associated cholangitis. For steroid-dependent disease, azathioprine has been used for maintenance of remission. Mycophenolate mofetil has been used for transplant immunosuppression and more recently for autoimmune hepatitis; however, there are no case reports to date on the use of mycophenolate mofetil in adult patients with autoimmune pancreatitis. A patient with IgG4-mediated autoimmune pancreatitis and IgG4-associated cholangitis refractory to steroids and intolerant of azathioprine was treated with mycophenolate mofetil, which inhibits de novo guanosine synthesis and blockade of both B and T lymphocyte production. Introduction of mycophenolate mofetil and uptitration to 1000 mg by mouth twice daily over a treatment period of 4 mo was associated with improvement in the patient’s energy level and blood glucose control and was not associated with any adverse events. The patient was managed without a biliary stent. However, there was a return of symptoms, jaundice, increase in transaminases, and hyperbilirubinemia when the prednisone dose reached 11 mg per day. In the first report of mycophenolate mofetil use in an adult patient with IgG4-associated autoimmune pancreatitis and IgG4-associated cholangitis, the introduction of mycophenolate mofetil was safe and well-tolerated without adverse events, but it did not enable discontinuation of the steroids. Mycophenolate mofetil and other immunomodulatory therapies should continue to be studied for maintenance of remission in the large subset of patients with refractory or recurrent autoimmune pancreatitis.

EUS-FNA for pancreatic neuroendocrine tumors: a tertiary cancer center experience

OBJECTIVES

Pancreatic neuroendocrine tumors (PNET) are fairly uncommon. Recent data highlight the importance of EUS in diagnosis of PNET. With this background, we decided to review our experience from a tertiary cancer center with regard to the presentation and clinical features of PNET and the diagnostic utility of EUS-FNA in this scenario.

METHODS

We identified patients who underwent EUS at our institution between January 1st 2001 and December 31st 2009 for a suspected PNET. Data on clinical features, cross-sectional imaging findings, EUS findings, and cytology results were collected.

RESULTS

A total of 81 patients were referred for EUS-FNA for a suspected PNET. Mean age was 58.1 years. There were 41 (50.6%) males. PNET was found incidentally in 38 (46.9%) patients. Computed tomography scanning identified a pancreatic mass in 72 out of 79 (91.1%) cases. Mean diameter of the largest lesion seen on EUS was 27.5 mm (range: 6.9-80 mm). The most common site (34; 42%) was the head of the pancreas. EUS-FNA correctly confirmed a PNET in 73 out of 81 cases with diagnostic accuracy of 90.1%. Seven (8.6%) out of 81 patients had functional lesions, including three gastrinomas and four insulinomas. Liver metastases were found in 31 out of 81 (38.3%) cases. Of the 31 patients with liver metastasis, the mean diameter of lesions on EUS was 33.9 mm compared with 23.5 mm in patients without liver metastasis (P = 0.005).

CONCLUSION

EUS-FNA is a reliable modality for further characterization of suspected lesions and for establishing a tissue diagnosis. The occurrence of complications of EUS-FNA in this setting is low. Non-functional PNET are more frequently encountered than functional PNET.

Endoscopic management of duodenal adenomas in familial adenomatous polyposis--a single-center experience

BACKGROUND

Duodenal lesions (DLS) are common in patients with familial adenomatosis polyposis (FAP), and screening for duodenal adenocarcinoma (DA) is currently recommended. Endoscopic treatment of DLS is controversial.

AIM

To report management and outcomes of endoscopic therapy for DLS in patients with FAP.

METHODS

The records of patients with FAP who underwent endoscopic surveillance or therapy for DLS over a 15-year period were reviewed. Endoscopic intervention included endoscopic surveillance with biopsies, argon plasma coagulation (APC), endoscopic mucosal resection (EMR), EMR with APC, and ampullectomy. Main outcome measurements were recurrence and histology of DLS after endoscopic therapy, complications of endoscopic therapy, and need for duodenectomy.

RESULTS

Seventy-one patients with FAP and DLS were identified from our endoscopy database as undergoing upper endoscopy for screening and/or surveillance (1995-2009). Mean follow up was 4.5 years (1-15 years). Seventy of the seventy-one (98.5%) patients had multiple flat DLS. Most of the patients were followed with yearly biopsies. APC was performed in 17 patients and EMR was performed in eight patients; in five of the eight EMR patients, APC was also performed to treat the edges of EMR site. During the follow up, 17/55 (31%) patients had histological progression (HP). HP was seen in 5/16 (31%) patients who underwent APC (one was lost to follow-up) and 12/40 (30%) patients followed with biopsies alone. Recurrence of lesions was noted in all patients. Two patients underwent duodenectomy. None of the patients developed DA during follow up.

CONCLUSIONS

Endoscopic surveillance with directed endotherapy for DLS in FAP is feasible and safe when diligently performed.

Predictors of colorectal cancer following a negative colonoscopy in the Medicare population

BACKGROUND

The incidence of colorectal cancer following a normal colonoscopy in the Medicare population is not known.

METHODS

A 5% national sample of Medicare enrollees from 1996 to 2005 was used to identify patients undergoing complete colonoscopy. A colonoscopy not associated with any procedure (e.g., biopsy, polypectomy or fulguration) was defined as a negative colonoscopy. Patients with history of inflammatory bowel disease, colorectal cancer or death within 12 months of colonoscopy were excluded. A multivariable model was constructed to evaluate the factors associated with a new diagnosis of colorectal cancer in the period from 12 to 120 months following the negative colonoscopy.

RESULTS

Among 200,857 patients (mean age 74 years, 61% female, 92% White) with a negative colonoscopy, the incidence of colorectal cancer was 1.8 per 1,000 person-years. The incidence rate for matched follow-up periods decreased from 2.0/1,000 person-years for patients undergoing colonoscopy during 1996-2000 to 1.2/1,000 person years during 2001-2005. Multivariate analysis revealed a significant regional variation in the incidence of colorectal cancer following a negative colonoscopy. The incidence was higher in patients >85 years, males and patients who underwent a negative colonoscopy by a non-gastroenterologist or endoscopist in the lowest volume quartile. On stratified analyses, endoscopist volume was a significant predictor for non-gastroenterologists only.

CONCLUSIONS

The specialty and experience of the endoscopist are significant predictors of the incidence rate of colorectal cancer in Medicare patients with a negative colonoscopy.

Human colonic myofibroblasts promote expansion of CD4+ CD25high Foxp3+ regulatory T cells

BACKGROUND & AIMS

Regulatory T (Treg) cells (CD4+ CD25high FoxP3+) regulate mucosal tolerance; their adoptive transfer prevents or reduces symptoms of colitis in mouse models of inflammatory bowel disease. Colonic CD90+ mesenchymal myofibroblasts and fibroblasts (CMFs) are abundant, nonprofessional antigen-presenting cells in the normal human colonic mucosa that suppress proliferation of activated CD4+ effector T cells. We studied CMF suppressive capacity and evaluated the ability of CMF to induce Treg cells.

METHODS

Allogeneic cocultures of CD4+ T cells and CMFs, derived from normal mucosa of patients undergoing colectomy for colon cancer or inflamed colonic tissues from patients with ulcerative colitis or Crohn's disease, were used to assess activation of the Treg cells.

RESULTS

Coculture of normal CMF with resting or naïve CD4+ T cells led to development of cells with a Treg phenotype; it also induced proliferation of a CD25+ CD127- FoxP3+ T cells, which expressed CTLA-4, interleukin-10, and transforming growth factor-β and had suppressive activities. In contrast to dendritic cells, normal CMFs required exogenous interleukin-2 to induce proliferation of naturally occurring Treg cells. Induction of Treg cells by normal CMFs required major histocompatibility complex class II and prostaglandin E2. CMFs from patients with inflammatory bowel diseases had reduced capacity to induce active Treg cells and increased capacity to transiently generate CD4+CD25+/- CD127+ T cells that express low levels of FoxP3.

CONCLUSIONS

CMFs suppress the immune response in normal colon tissue and might therefore help maintain colonic mucosal tolerance. Alterations in CMF-mediated induction of Treg cells might promote pathogenesis of inflammatory bowel diseases.

Optimum palliation of inoperable hilar cholangiocarcinoma: comparative assessment of the efficacy of plastic and self-expanding metal stents

BACKGROUND

Endoscopic retrograde biliary drainage (ERBD) with plastic or self-expanding metal stents (SEMS) is often performed for palliative care for cholangiocarcinoma.

OBJECTIVE

The objective was to compare the clinical effectiveness, including stent patency, complication rate, and need for salvage percutaneous transhepatic biliary drainage, of SEMS and plastic stents.

METHODS

A total of 100 patients with inoperable cholangiocarcinoma were identified from an endoscopic database from 1/1/01 to 9/30/06 at a tertiary cancer hospital and their clinical history was retrospectively reviewed. All patients were followed to death, re-intervention, or for at least one year. Stent patency and patient survival were estimated by Kaplan-Meier analysis, supplemented by the log-rank test for comparisons between groups.

RESULTS

Forty-eight patients had SEMS placed and 52 patients had plastic stents placed. ERBD was successful in 46 (95.8%) in the SEMS group and 49 (94.2%) in the plastic group (P = 0.67). Median patency times were 1.86 months in the plastic group and 5.56 months in the SEMS group (P < 0.0001). A mean of 1.53 and 4.60 re-interventions were performed in the SEMS and plastic groups, respectively (P < 0.05). Complications occurred in 4/48 (8.3%) in the SEMS group and 4/52 (7.7%) in the plastic group (P = 0.79). Median survival was 9.08 and 8.22 months in the SEMS and plastic stent groups, respectively (P = 0.50).

CONCLUSION

Metallic stent patency was superior to that of plastic stents in all Bismuth-Corlette classifications of hilar cholangiocarcinoma with similar complication rates. SEMS seem to be cost-effective and, when feasible, should be considered as an initial intervention in patients with inoperable hilar cholangiocarcinoma.

Endoscopic sutured closure of a gastric natural orifice transluminal endoscopic surgery access gastrotomy compared with open surgical closure in a porcine model. A randomized, multicenter controlled trial

BACKGROUND AND STUDY AIMS

In natural orifice transluminal endoscopic surgery (NOTES) procedures it is essential to be able to perform secure closure of the access perforation. The aim of this study was to compare endoscopically sutured closure of a gastric access gastrotomy using the tissue apposition system (TAS), with closure via laparotomy in a randomized multicenter study.

METHODS

A total of 32 pigs (18 - 42 kg) were used in this study. The gastric NOTES access was created using a needle knife and a 20-mm balloon. Following transgastric pelvic peritoneoscopy, the endoscope was withdrawn into the stomach. The animals were then randomized to endoscopic closure or laparotomy with surgical closure. Procedure time, recovery time, and weight gain were measured. At necropsy, adhesions, abscesses or peritonitis were recorded.

RESULTS

Of the 32 pigs, 29 survived 14 days without complications. All endoscopic and all open surgical closures were secure at postmortem. On average two suture pairs were used for endoscopic closure. Surgical closure was quicker (12.5 vs. 20.1 minutes). Recovery time and postoperative weight gain were similar for both groups. Two pigs in the endoscopic group died: one of gastric dilatation, without leakage from the gastrotomy; another was euthanized due to rectal prolapse. In the laparotomy group one pig was euthanized after 7 days due to abdominal wound dehiscence. At necropsy there were significantly more intra-abdominal adhesions in the laparotomized group.

CONCLUSION

This randomized controlled study of endoscopic and surgical closure of a gastrotomy made for transperitoneal access for NOTES procedures suggests that both techniques are comparable in technical closure rates, postoperative recovery, and prevention of peritonitis. There were fewer adhesions in the endoscopic group.

Colonoscopic full-thickness resection of the colon in a porcine model as a prelude to endoscopic surgery of difficult colon polyps: a novel technique (with videos)

BACKGROUND

Colonoscopic full-thickness resection (CFTR) of the colon may obviate the need for surgical resection of benign lesions.

OBJECTIVE

To develop an animal model for CFTR of the colon followed by endoscopic suture closure with through-the-endoscope devices.

DESIGN

Pilot study.

SETTING

University medical center.

ANIMALS

Twenty pigs.

INTERVENTIONS

A 2-cm circular area was resected on the antimesenteric side of the colon (phase 1, n = 10) and on the mesenteric side (phase 2, n = 10) by using an insulated tip knife cut followed by the use of a grasping forceps and a snare to resect and retrieve the specimen. The tissue apposition system was used to close the defect.

MAIN OUTCOME MEASUREMENTS

Resection and closure times were recorded. The animals were euthanized at 2 weeks and examined for peritonitis, adhesions, wound healing, and T-tag injury to adjacent viscera.

RESULTS

The CFTR was successful in all 20 attempts. The median resection time was 6 minutes (range 2.5-35 minutes). Suture closure was successful in 19 animals. It took a median time of 41 minutes (range 21-125 minutes) and 4 sutures to close the defect. Eighteen animals survived without clinical signs of distress; there was a well-healed scar without peritonitis or distant adhesions on necropsy at 2 weeks. One animal failed to thrive, and necropsy revealed mild peritonitis, small abscesses, distant adhesions, and a 2-mm hole at the suture site. Two of the 132 T-tags were inserted in the adjacent viscera.

LIMITATIONS

Colon resection in the proximal colon was not studied.

CONCLUSIONS

In this animal model, CFTR of the colon followed by suture closure can be accomplished successfully by using through-the-endoscope devices.

PD-1 ligand expression by human colonic myofibroblasts/fibroblasts regulates CD4+ T-cell activity

BACKGROUND & AIMS

A prominent role for inhibitory molecules PD-L1 and PD-L2 in peripheral tolerance has been proposed. However, the phenotype and function of PD-L-expressing cells in human gut remains unclear. Recent studies suggest that colonic myofibroblasts (CMFs) and fibroblasts are important in the switch from acute inflammation to adaptive immunity. In the normal human colon, CMFs represent a distinct population of major histocompatibility complex class II(+) cells involved in the regulation of mucosal CD4(+) T-cell responses.

METHODS

PD-L1 and PD-L2 expression on human CMFs was determined using Western blot, fluorescence-activated cell sorter analysis and confocal microscopy. Lymphoproliferation assays and cytokine enzyme-linked immunosorbent assays were used to evaluate the role of B7 costimulators expressed by CMFs with regard to the regulation of preactivated T-helper cell responses.

RESULTS

We demonstrate here the expression of PD-L1/2 molecules by normal human CMF and fibroblasts in situ and in culture. Both molecules support suppressive functions of CMFs in the regulation of activated CD4(+) T-helper cell proliferative responses; blocking this interaction reverses the suppressive effect of CMFs on T-cell proliferation and leads to increased production of the major T-cell growth factor, interleukin (IL)-2. PD-L1/2-mediated CMF suppressive functions are mainly due to the inhibition of IL-2 production, because supplementation of the coculture media with exogenous IL-2 led to partial recovery of activated T-cell proliferation.

CONCLUSIONS

Our data suggest that stromal myofibroblasts and fibroblasts may limit T-helper cell proliferative activity in the gut and, thus, might play a prominent role in mucosal intestinal tolerance.

American Gastroenterological Association (AGA) Institute technical review on obscure gastrointestinal bleeding

This literature review and the recommendations therein were prepared for the AGA Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on March 12, 2007, and by the AGA Institute Governing Board on May 19, 2007.

American Gastroenterological Association (AGA) Institute medical position statement on obscure gastrointestinal bleeding

This document presents the official recommendations of the American Gastroenterological Association (AGA) Institute on "Evaluation and Management of Occult and Obscure Gastrointestinal Bleeding." It was approved by the Clinical Practice and Economics Committee on March 12, 2007, and by the AGA Institute Governing Board on May 19, 2007. This medical position statement is based upon the interpretation and assimilation of scientifically valid research, derived from a comprehensive review of published literature.